Recently, for example, a system has been suggested and practically used, in which a gyroscope is used for a navigation system of an automobile to detect the compass direction or the like of the automobile.
Especially, an optical fiber gyroscope has been suggested, which is extremely advantageous in operability, convenient handling performance, and realization of a compact and light weight system, and which is also advantageous in improvement in durability because there is no mechanically movable component. Development is being rapidly advanced at present in order to practically use such an optical fiber gyroscope.
When it is intended to produce the optical fiber gyroscope which is excellent in, for example, compact and light weight properties and durability as described above, the process for assembling the optical fiber gyroscope especially comprises the steps of winding a lengthy optical fiber around a cylindrical object to produce a fiber coil, optically coupling an optical IC chip (optical waveguide) incorporated with a phase modulator to two ends of the optical fiber led from the fiber coil, optically coupling an optical fiber led from a light source to an optical fiber to be led to a photodetector by using a coupler, optically coupling an optical fiber led from the coupler to the optical IC chip, and packaging the optical IC chip. In this case, a problem arises in that the operation for assembling such an optical fiber gyroscope is extremely complicated.
Especially, the fiber coil comprises the optical fiber which is merely wound around the cylindrical object. Therefore, the wound state is sometimes loosened during the assembling operation, and the cylindrical object is rotated by the human hand one by one to perform the operation. Such an operation is extremely troublesome. When the optical IC chip is packaged, it is necessary to support the long optical fiber in one bundle so that no excessive load is exerted on the optical IC chip by the long optical fiber. As a result, a problem arises in that the operation efficiency is deteriorated.
As described above, the conventional optical fiber gyroscope involves the problems that the assembling operation requires extremely long time, and there is a limit to reduce the production cost.
The present invention has been made taking such problems into consideration, an object of which is to provide a reel for a fiber coil, which makes it possible to easily assemble an optical fiber gyroscope and effectively reduce the production cost of the optical fiber gyroscope.